Many players constantly obsess over their strokes, rightfully wanting to have "perfect technique." While that's admirable, it often keeps them from reaching their full potential. Why? Because the obsession with perfect technique often comes at the expense of developing consistency, serves, and receive. (Plus, what is "perfect technique"? Not all of the best players have the same technique.)
Especially for players who have played a long time, trying to change technique is difficult and time-consuming. Instead, assuming the players had pretty good technique, the time might instead be used for developing consistency with those techniques, developing great serves, and mastering receive. If players obsessed over these as much as having "perfect technique," many would reach higher levels.
This doesn't mean one shouldn't try to develop great technique - but it's all about the law of diminishing returns. Kids, and beginners without bad habits already ingrained, should focus on great technique. Others might settle for good (or perhaps very good) technique - and then, by using that technique for years, develop consistency without going for that elusive "perfect technique." Meanwhile, few players really develop their serves to a high level, and even fewer become good at receive, which is often called "everyone's weakness."
So if you have good technique, discuss with a coach the relative advantages of going for perfect technique in limited practice time, versus working toward consistency, serve, and receive. Because guess what? Most matches below the highest levels are won on those three.